Depression of gangue during flotation



ZUB. ULASSIWWG. SEPARATING (it ASSURTING .SULIUS Patented Aug. 13, 1940 UNITED STATES In both cases, the present invention greatly reduces the adverse effect of the different types of gangue.

It is an advantage of the present invention that it is applicable to finely divided gangues of StAriCH BOO;

PATENT OFFICE DEPRESSION F GANGUE DURING FLOTATION Robert B. Booth, Springdale, Conn., assignor to American Cyanamid Company, New York, a

N. Y., a corporation oi Maine No Drawing. Application June 28, 1938,

Serial No. 216,291

13 Claims. (01. 209-166) This invention relates to froth flotation the most varied types of ores, such as precious processes and in particular, to the flotation of metal ores, base metal ores, non-metallics and ores having slimy gangues. the like. The property of inhibiting the unde- In the past, much difficulty has been encounsirable effects of finely divided gangue appears tered with certain ores in which some or all of to be a general one possessed in high degree by the gangue constituents have been present as all acid dyestuffs, and in considerable degree by fine slimes which have hindered flotation. The dyestuffs which possess solubilizing groups other slimes have sometimes been ordinary gangue than sulfonic acid groups. The efliciency of the minerals, such as those of a generally silicious different dyes will vary to some extent, but they nature, and sometimes have been carbonaceous. all possess the property of modifying gangue so While it is often possible to deslime ores prior 88 to inhibit its undesirable effects. Among the to treatment by froth flotation, this is not aldyes, I have found that water-soluble nigrosine ways feasible because in many cases certain com- (sulfonated nigrosine) and sun yellow are among ponents of the slime carry with them recoverable the most efficient and at the same time are values or, in other cases, it is necessary to grind readily available. the feed to a very fine size so that practically The exact mechanism by which the dyes aflect all of the feed might be considered as a slime. the surfaces of the gangue is not as yet definitely h present ntion i dir t d to a, froth known, and the invention is not intended to be flotation process in which the gangue is modified, limited to any particular e y of actionand more particularly the fine gangue, by the ad- It is an advantage of the present invention dition of a class of reagents so that although it that the dyestuff while they may be used alone is not removed prior to froth flotation, it does h great eflect, can also be combined with not adversely affect the flotation operation or er ypes of gengue modifiers. such as for exits adverse effects are to a great extent limited. mple li 'nin sulfonates as described and claimed The present invention is based on the discovn e applications o Breerwood. Se al No. 5 ery that dyestuffs having solubilizing groupings, 3. d serial 163.303 both filed l and particularly acid dyestuffs containing cartember 10, 1937; dextrin as described and claimed boxyl or sulfonic groups or both, exert an action in my cop d pp Serial 138,075 on gangue, preventing interference with froth filed ua y 1938; crude su ar residues as flotation both in the case of fine silicious gangue described and claimed in my copending appliand also in the case 01 carbonaceous gangue, cation, Serial N0. 211,811 flled June 4, 1938; and particularly with precious metal ores. the like- In some of the examples, the use of The mechanism of the interference of the p c mixtures is described. gangue with the flotation is probably not the The invention will be ri e in greater same in all cases, and the present invention is detail n Conjunction with the following specific 5 not intended to be limited to any particular e amples, the flotation being in eve y case in theory of action of the finely divided gangue or Standard Fagerglen flotation machines xcept of the solubilized dyestuffs thereon. In the case for mp 7 in which a small e pecial laboof silicious gangue, it is probable that the gangue retory c e was used. modifies the surfaces of the values and reduces recovery, whereas the dyestuffs of the present Emmplel invention appear. to so alter or modify the sur- A carbonaceous gold ore om the Mother faces of the fine gangue particles that they no 'i r t c nta s d. pyr ma netite. longer exert this deleterious action or exert it ersenopyrite. oheloopyrite. q te. musto a very greatly reduced extent. In the case smite and carbonaceous material. d assaying of carbonaceous gangue in carboncaeous precious 0133 to 0-190 Au D Fe. 0.80% C, metal ores, the above factor is not the only one and about 73% insoluble, was j ted to flobecause the carbon also contaminates the contation With and without a dye as ga ue modicentrate and adversely affects cyanidation of her. The ore pulp was conditioned with 0.15 lb. the concentrate which is commonly practiced. p r ton f s h. .21 l per ton of copper sulfate pentahydrate, 0.08 lb. per ton of potassium ethyl xanthate, 0.010 lb. per ton of potassium secondary butyl xanthate, 0.10 lb. per ton of a fifty-fifty mixture of sodium diethyland disecondary butyl-dithiophosphates, and 0.062

lb. per ton of pine oil. The following gangue modifiers were also used: 0.50 lb. per ton of water-soluble.nigrosine in test #2, 0.5 lb. per ton of a fifty-fifty mixture of water-soluble nigrosine and a dried molasses residue in test #3, 0.5 lb. per ton of a fifty-fifty mixture of water-soluble nigrosine and calcium lignin sulfonate in test #4, 0.50 lb. per ton of a fifty-fifty mixture of water-soluble nigrosine and yellow corn dextrine netite, limonite and quartz, and assaying 0.308 to 0.327 oz. Au per ton, 0.06% Cu, 2.95% Fe, 0.38% S and about 92% insoluble, was floated. This ore presented a slime interference during flotation. The pulp was conditioned with the following reagents: 0.15 lb. per ton of potassium secondary butyl xanthate, 0.05 lb. per ton of a fifty-fifty mixture of sodium diethyland discoondary butyl-dithiophosphates, and 0.062 lb. per

in test #5, and no gangue modifier was used in ton of pine oil. The following gangue modifiers test #1. were also used: 2.0 lbs. per ton of a stilbene dye,

Feed Concentrate Teiling Test No.

G Oz. Au, Weight, Ratio Oz. Au, Percent Weight, Oz. Au, Percent ton percent conc n An recov. percent ton Au recov.

002. 4 0.190 14 34 7.0 1 1. 200 95. 20 35. 55 0.010 4 14 003. 5 0.154 5 12 17. 5 1 2. 530 94.13 94 2s 0.010 5. 84 5050 0.138 5 52 17. 8/1 2.240 91. 30 94. 33 0.013 3.10 000. 2 0.158 s 14. 4/1 2. 280 94 04 93. 04 0.010 5. 30 004.9 0.154 e 93 14. 4/1 2.120 95.45 93. 07 0.008 4.55

Example 2 sun yellow, in test #11; 0.25 lb. per ton of water- A carbonaceous gold ore from South Africa containing pyrite, chalcopyrite, bornite, pyrrhotite, quartz and carbonaceous material, and assaying 0.263 to 0.280 oz. Au per ton, 0.975% S, 1.47% C, and about 91% insoluble, was subjected soluble nigrosine in test #12; and no gangue modifier was used in test #10. The results of these tests were compared with those obtained by using 2.0 lbs. per ton of soda ash (test #13) and 2.0 lbs per ton of sodium silicate (test #14),

to flotation with and without a dye as gangue two reagents frequently used to overcome slime modifier. The ore was conditioned with 0.35 lb. interference during flotation.

Feed Concentrate 'Ieiilng Test No.

G Oz. Au, Weight, Ratio Oz. Au, Percent Weight, Oz. Au, Percent ton percent conc. ton Au recov. percent 11 Au recov.

59s. 0 0. 320 5. 92 10. 9 1 4. 020 84. 05 94. 0s 0. 055 15. 95 904. 2 0. 321 3. 2e 30. 1/1 7. 900 79. 20 90. 14 0. 010 20. so 505. 4 0. 325 1. 22 92. 0 1 21. 913 82. 45 03. 7s 0. 05s 11. 54 000. 0 0. 30s 5. 11 19. 3 1 4 900 32. 14 94. 83 0. 05s 11. so 603. 5 0. 319 4. 2s 23. 0 1 5. 200 92. 13 95. 11 0. 000 11. 81

per ton of potassium secondary butyl xanthate, Example 4 0.03 lb. per ton of a fifty-fifty mixture of sodium diethyland disecondary butyl-dithiophosphates, and 0.062 lb. per ton of pine oil. The following gangue modifiers were also used: 1.0 lb per ton of water-soluble nigrosine in test #7, 1.0 lb. per ton of a stilbene dye, sun yellow, in test #8, 1.0 lb. per ton of an anthraquinone dye, alizarin saphirol B, in test #9, and no gangue modifier in test #6.

A copper ore containing about 1% Cu and about 64% insoluble, including a large amount of talcose material, was subjected to flotation with and without water-soluble nigrosine as a gangue modifier. In test #16 the ore was conditioned first with 0.25 lb. per ton of water-soluble nigrosine and then with 0.15 lb. per ton of potassium Feed Concentrate Telling Test No.

G Oz. Au, Weight, Ratio Oz. Au, Percent Weight, Oz. Au, Percent ton percent conc. ton Au recov. percent ton Au recov.

Example 3 secondary butyl xanthate and 0.0621b. per ton of A gold ore from the Philippine Islands containing gold, pyrite, chalcopyrite, azurite, magpine oil; in test #15 no water-soluble nigrosine was used.

Feed Concentrate Tailing Test No.

G. Percent Percent Ratio Percent g a Percent Percent 6 8 Cu weight conc. Cu tecov welght Cu rem (1 sows As demonstrated by theabove examples, the use of the dyes as gangue modifiers in the case of both the gold ores and the copper ore resulted in an increased ratio of concentration.

Example 5 SEARCH R00? 2. A method of froth flotation of materials containing floatable metals or metal compounds and finely divided carbonaceous gangue which normally exerts a deleterious action on flotation, said materials being substantially free from molybdenum sulfide, which comprises subjecting the material to flotation in the presence of a collector without removing the gangue and depressing the gangue by means of an effective amount of a dyestuff containing a solubilizing group included in the group consisting of carboxyl, sulfonic, and their salts.

3. A method of froth flotation of materials containing floatable metals or metal compounds and sing (test #17). finely divided substantially barren non-metallif- Feed Concentrate 'Iailing Test No.

G 0500:, Weight, Ratio C8003, ggg g Weight, 0300., 333 percent percent cone. percent recov? percent percent It will be noted that by the use of water-soluble nigrosine. an increase in weight, recovery, grade of concentrate, and recovery of CaCOa in concentrate resulted.

Example 6 Tests have shown that the behaviour of gangue depressants for carbonaceous precious metal ores can be accurately predicted by their action on pure graphite in a small laboratory flotation machine. The results are completely reliable qualitatively and reliable quantitatively with a moderate degree of accuracy. A large number of dyes were tested out in the laboratory machine for their action on graphite slime, the tests being erous gangue which normally exerts a deleterious action on flotation, said materials being substantially free from molybdenum sulfide, which comprises subjecting the material to flotation in the presence of a collector without removing the gangue and depressing the gangue by means of an effective amount of water-soluble nigrosine.

4. A method of froth flotation of materials containing floatable metals or metal compounds and finely divided carbonaceous gangue which normally exerts a deleterious action on flotation, said materials being substantially free from molybdenum sulfide, which comprises subjecting the material to flotation in the presence of a collector as follows: without removing the gangue and depressing the Floated Tailings No. of Feed, Floated, l gs. percent percent dye color Dye name Dye class weight weight Index N in wet r sol Azine 25. l l. 3 23. 8 5. 18 94. 82 865 ln gi i ii ne fu f do 25. 0 9. 3 15- 7 37- 20 62. Diamond Black PV. Azo (chrome) 25.0 1.3 23. 7 5. 20 94. 80 Alizarin Saphirol B Azitlagaquinone 25.2 0.9 24.3 3.57 96.43 1054 am Allzarin Sky Blue B .do 25. 2 1. 8 23. 4 7.14 92. 86 1088 Methyl Cotton Blue. Triiphsiylmethane 25. l 1.4 23. 7 5. 58 94. 42 706 no Patent Blue A do 25.2 2. 4 22. 8 9. 52 90. 48 714 Diamine Green B Azo (direct) 25. l 8.4 16. 7 33. 47 66. 53 593 Spirit Orange Am (acid) 25. 2 2. 7 22. 5 10. 71 89. 29 Spirit Red do 24. 9 l. 9 23. 0 7. 63 92. 37 652 Violamine R Xenthene (acid) 25.2 3. 4 21.8 13.49 86.51 758 Methyl Violet B Trdphenylmethane 25. l 8.2 16. 9 32. 67 67. 33 680 asic Sun Yellow Stilbene (direct) 24. 7 0. 7 0 83 97. 17 620 Sap Brown Sol. Earth oolor 25. l 4.3 8 13 32. 87

2; it i3? uinoline e ow uino ins aci yanthrolG Antiifiaquinone 25.1 1.7 2 .4 .77 93.23 1077 The results of these tests indicate that the dyes are efiective depressants for graphite.

What I claim is:

1. A method of froth flotation of materials containing floatable metals or metal compounds and finely divided substantially barren non-metalliferous gangue which normally exerts a deleterious action on flotation, said materials being substantially free from molybdenum sulfide, which comprises subjecting the material to flotation in the presence of a collector without removing the gangue and depressing the gangue by means of an effective amount of a dyestuif containing a solubilizing group included in the group consisting of carboxyl, sulfonic, and their salts.

gangue by means of an effective amount of watersoluble nigrosine.

5. A method of froth flotation of materials containing fioatable metals or metal compounds and finely divided substantially barren non-metalliferous gangue which normally exerts a deleterious action on flotation, said materials being substantially free from molybdenum sulfide, which comprises subjecting the material to flotation in the presence of a collector wthout removing the gangue and depressing the gangue by means of an effective amount of sun yellow.

6. A method of froth flotation of materials containing floatable metals or metal compounds and finely divided carbonaceous gangue which normally exerts a deleterious action on flotation, said materials being substantially free from molybdenum sulfide, which comprises subjecting the material t6 flotation in the presence of a collector without removing the gangue and depressing the gangue by means of an effective amount of sun yellow.

7. 'A method of froth flotation of carbonaceous precious metal ores which comprises carrying out the froth flotation without preliminary removal of carbonaceous gangue and depressing the gangue by means of a dyestufi having solubilizing groups included in the group consisting of carboxyl, sulfonic and their salts.

8. A method of froth flotation of carbonaceous precious metal ores which comprises carrying out the froth flotation without preliminary removal of carbonaceous gangue and depressing the gangue by means of water-soluble nigrosine.

9. A method of froth flotation of carbonaceous precious metal ores which comprises carrying out the froth flotation without preliminary removal of carbonaceous gangue and depressing the gangue by means of sun yellow.

10. A method of froth flotation of non-metallics in the presence of finely divided gangue which,

normally exerts a deleterious action on flotation which comprises carrying out the flotation without removing the fine gangue and depressing the gangue by means of a dyestufi having solubilizing groups included in the group consisting of carboxyl, sulfonic and their salts.

11. A method of froth flotation of non-metallies in the presence of finely divided gangue which comprises carrying out the flotation without removing the fine gangue and depressing the gangue by means of water-soluble nigrosine.

12. A method according to claim 10 in which the material floated is a cement rock raw material.

13. A method according to claim 11 in which the material floated is a cement rock raw ma- 20 terial.

ROBERT B. BOOTH. 

